The present invention relates to an air bag module and in particular an air bag module assembly.
Most motor vehicles are provided with an air bag module that is mounted to the vehicle in order to deploy in a manner so as to protect the vehicle occupant. For example, a driver""s side air bag module includes a generally toroidal inflator positioned partially within a bag opening of an air bag for discharging inflator gas to inflate the air bag upon sensing certain predetermined vehicle conditions.
The undeployed air bag is folded atop the inflator and a module cover overlies the air bag, inflator and other module components. The cover commonly has tear lines or weakened portions that allow the cover to open during air bag inflation.
Typically, the inflator includes a main body portion which discharges gas and the inflator has an outwardly extending inflator mounting flange. The module also includes an air bag retainer. The air bag retainer is located within the bag opening of the air bag and including a central gas opening for receiving the inflator therethrough.
It is also typical to connect the air bag retainer to the air bag by a first fastening mechanism, to connect the air bag retainer to the base plate by a second fastening mechanism, and to connect the inflator to the base plate by a third fastening mechanism. The air bag retainer, air bag, inflator, and cover are each connected to the base plate to form the air bag module. Typically, the first, second, and third fastening mechanisms are each composed of one or more parts.
In addition, the module typically includes a plurality of axially elongated mounting members or female fasteners mounted to the base plate to connect the module to a hub portion of a steering wheel. In some applicaitons the module perimeter is wider than a perimeter of the steering column of a steering wheel assembly, the mounting members on the base plate are located outboard of the perimeter of the steering column such that access holes can be provided in the hub portion directly beneath the mounting members for rear release of the mounting members for disconnection of the module from the steering wheel.
In addition, and in some applications the multiplicity of fastening mechanisms required to retain the module components to each other along with the mounting members required to mount the module to the steering wheel greatly increases assembly time.
The present invention preferably provides a module having mounting members which both retain the components of the air bag module and which also mount the module to the vehicle. Advantageously, the present invention simplifies the module by reducing the number of fastening components in the module, thus reducing mass, cost and assembly steps.
In accordance with an exemplary embodiment of the present invention, the air bag cushion retaining ring is completely removed from the air bag module design. The air bag cushion is secured to the inflator flange by being sandwiched in between a retaining member and the inflator flange. In addition, mounting studs pass through apertures in the air bag cushion. The assembly is held together by a plurality of fastening members which are secured to the plurality of mounting studs causing a base plate and the inflator flange to provide surfaces for securing the air bag cover retaining members and the air bag cushion.
In an exemplary embodiment, the module preferably enables easy snap-fitted attachment of the module to the vehicle using the same mechanism that retains the components.
The above-described and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims.